Atlas-based segmentation (ABS) is a well-established and widely used technique for extracting contours in medical images. Generally, ABS is a commonly used method for segmenting medical images. An atlas contains the locations and shapes of organs and/or lesions along with the spatial relationships between them. There are different commonly-used ways to generate an atlas, including: (i) an expert manually segments selected images; or (ii) software generates an atlas by reading and processing multiple segmented images (from one or multiple experts). When an atlas is available then new (unseen) images can be contoured and/or segmented by mapping their coordinate space to that of the atlas, such that the anatomical boundaries are correctly marked (a process called image registration). In the registration process the images in the atlas are registered against the new image. The registered images are then compared against the new image to find the best matching registered image. Afterward, the corresponding image transformation, obtained by the registration process, is applied to the contour of the best matching image. The contour is then deformed and mapped to the new image.
The accuracy of the ABS mainly depends on two factors: (i) the size of the atlas; and (ii) the performance of image registration. Large atlases (meaning atlases that comprise one or multiple atlases) and sophisticated registration algorithms can be employed to increase the accuracy of the contouring. However, using large and comprehensive atlases can reduce computational efficiency such that the results can be provided after long searching and registration times.
Prior art ABS systems and methods are disclosed in the following prior art references: U.S. Pat. No. 6,901,156 having the title METHOD, SYSTEM AND COMPUTER READABLE MEDIUM FOR AN INTELLIGENT SEARCH WORKSTATION FOR COMPUTER ASSISTED INTERPRETATION OF MEDICAL IMAGES;
U.S. Pat. No. 6,950,544 having the title AUTOMATED MEASUREMENT OF ANATOMICAL STRUCTURES IN MEDICAL IMAGING;
U.S. Pat. No. 7,245,766 having the title METHOD AND APPARATUS FOR DETERMINING A REGION IN AN IMAGE BASED ON A USER INPUT;
U.S. Pat. No. 7,324,842 having the title ATLAS AND METHODS FOR SEGMENTATION AND ALIGNMENT OF ANATOMICAL DATA;
U.S. Pat. No. 7,324,842 having the title ATLAS AND METHODS FOR SEGMENTATION AND ALIGNMENT OF ANATOMICAL DATA;
U.S. Pat. No. 7,327,138 having the title METHOD FOR GENERATING AN MR ATLAS AND FOR MR IMAGING USING SAME;
U.S. Pat. No. 7,333,644 having the title SYSTEMS AND METHODS FOR PROVIDING AUTOMATIC 3D LESION SEGMENTATION AND MEASUREMENTS;
U.S. Pat. No. 7,340,082 having the title METHOD AND MEDICAL IMAGING APPARATUS FOR DETERMINING A SLICE IN AN EXAMINATION VOLUME FOR DATA ACQUISITION IN THE SLICE;
U.S. Pat. No. 7,346,201 having the title SEMI-AUTOMATED MEASUREMENT OF ANATOMICAL STRUCTURES USING STATISTICAL AND MORPHOLOGICAL PRIORS;
U.S. Pat. No. 7,394,946 having the title METHOD FOR AUTOMATICALLY MAPPING OF GEOMETRIC OBJECTS IN DIGITAL MEDICAL IMAGES;
U.S. Pat. No. 7,584,080 having the title CONSTRUCTING A STATISTICAL SHAPE MODEL FROM TWO-DIMENSIONAL OR THREE-DIMENSIONAL DATA;
U.S. Pat. No. 7,623,709 having the title METHOD AND SYSTEM FOR SEGMENTING IMAGE DATA;
U.S. Pat. No. 7,646,898 having the title METHODS AND APPARATUS FOR PROCESSING MEDICAL IMAGES;
U.S. Pat. No. 7,773,786 having the title METHOD AND APPARATUS FOR THREE-DIMENSIONAL INTERACTIVE TOOLS FOR SEMI-AUTOMATIC SEGMENTATION AND EDITING OF IMAGE OBJECTS;
U.S. Pat. No. 7,792,348 having the title METHOD AND APPARATUS OF USING PROBABILISTIC ATLAS FOR CANCER DETECTION;
U.S. Pat. No. 7,817,836 having the title METHODS FOR VOLUMETRIC CONTOURING WITH EXPERT GUIDANCE;
U.S. Pat. No. 7,822,244 having the title SEGMENTING MEDICAL IMAGE DATA SETS;
U.S. Pat. No. 7,822,291 having the title NON-RIGID MULTI-MODAL REGISTRATION USING STATISTICAL LEARNING METHODS;
U.S. Pat. No. 7,831,079 having the title SEGMENTATION OF ANATOMIC STRUCTURES USING NAVIGATION TABLE;
U.S. Patent Application Publication No. 20030139659 having the title ATLAS AND METHODS FOR SEGMENTATION AND ALIGNMENT OF ANATOMICAL DATA;
U.S. Patent Application Publication No. 20030228042 having the title METHOD AND SYSTEM FOR PREPARATION OF CUSTOMIZED IMAGING ATLAS AND REGISTRATION WITH PATIENT IMAGES;
U.S. Patent Application Publication No. 20050031202 having the title IMAGE REGION SEGMENTATION SYSTEM AND METHOD;
U.S. Patent Application Publication No. 20050069183 having the title SEMI-AUTOMATED MEASUREMENT OF ANATOMICAL STRUCTURES USING STATISTICAL AND MORPHOLOGICAL PRIORS;
U.S. Patent Application Publication No. 20080267468 having the title SYSTEM AND METHOD FOR SEGMENTING A REGION IN A MEDICAL IMAGE;
U.S. Patent Application Publication No. 20090226060 having the title METHOD AND SYSTEM FOR IMPROVED IMAGE SEGMENTATION;
U.S. Patent Application Publication No. 20100266170 having the title METHODS AND SYSTEMS FOR FULLY AUTOMATIC SEGMENTATION OF MEDICAL IMAGES;
U.S. Patent Application Publication No. 20100286995 having the title INTERACTIVE ATLAS TO IMAGE REGISTRATION;
U.S. Patent Application Publication No. 20100295848 having the title INTERACTIVE IMAGE SEGMENTATION;
U.S. Patent Application Publication No. 20110013818 having the title 3D MEDICAL IMAGE SEGMENTATION;
U.S. Patent Application Publication No. 20090297014 having the title SYSTEM FOR ASSESSING RADIATION TREATMENT PLAN SEGMENTATIONS; and
U.S. Patent Application Publication No. 20090226060 having the title METHOD AND SYSTEM FOR IMPROVED IMAGE SEGMENTATION.